<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Mail
 * @subpackage Protocol
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Smtp.php 18951 2009-11-12 16:26:19Z alexander $
 */


/**
 * @see Zend_Mime
 */
require_once 'Zend/Mime.php';


/**
 * @see Zend_Mail_Protocol_Abstract
 */
require_once 'Zend/Mail/Protocol/Abstract.php';


/**
 * Smtp implementation of Zend_Mail_Protocol_Abstract
 *
 * Minimum implementation according to RFC2821: EHLO, MAIL FROM, RCPT TO, DATA, RSET, NOOP, QUIT
 *
 * @category   Zend
 * @package    Zend_Mail
 * @subpackage Protocol
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Mail_Protocol_Smtp extends Zend_Mail_Protocol_Abstract
{
	/**
	 * The transport method for the socket
	 *
	 * @var string
	 */
	protected $_transport = 'tcp';


	/**
	 * Indicates that a session is requested to be secure
	 *
	 * @var string
	 */
	protected $_secure;


	/**
	 * Indicates an smtp session has been started by the HELO command
	 *
	 * @var boolean
	 */
	protected $_sess = false;


	/**
	 * Indicates the HELO command has been issues
	 *
	 * @var unknown_type
	 */
	protected $_helo = false;


	/**
	 * Indicates an smtp AUTH has been issued and authenticated
	 *
	 * @var unknown_type
	 */
	protected $_auth = false;


	/**
	 * Indicates a MAIL command has been issued
	 *
	 * @var unknown_type
	 */
	protected $_mail = false;


	/**
	 * Indicates one or more RCTP commands have been issued
	 *
	 * @var unknown_type
	 */
	protected $_rcpt = false;


	/**
	 * Indicates that DATA has been issued and sent
	 *
	 * @var unknown_type
	 */
	protected $_data = null;


	/**
	 * Constructor.
	 *
	 * @param  string  $host
	 * @param  integer $port
	 * @param  array   $config
	 * @return void
	 * @throws Zend_Mail_Protocol_Exception
	 */
	public function __construct($host = '127.0.0.1', $port = null, array $config = array())
	{
		if (isset($config['ssl'])) {
			switch (strtolower($config['ssl'])) {
				case 'tls':
					$this->_secure = 'tls';
					break;

				case 'ssl':
					$this->_transport = 'ssl';
					$this->_secure = 'ssl';
					if ($port == null) {
						$port = 465;
					}
					break;

				default:
					/**
					 * @see Zend_Mail_Protocol_Exception
					 */
					require_once 'Zend/Mail/Protocol/Exception.php';
					throw new Zend_Mail_Protocol_Exception($config['ssl'] . ' is unsupported SSL type');
					break;
			}
		}

		// If no port has been specified then check the master PHP ini file. Defaults to 25 if the ini setting is null.
		if ($port == null) {
			if (($port = ini_get('smtp_port')) == '') {
				$port = 25;
			}
		}

		parent::__construct($host, $port);
	}


	/**
	 * Connect to the server with the parameters given in the constructor.
	 *
	 * @return boolean
	 */
	public function connect()
	{
		return $this->_connect($this->_transport . '://' . $this->_host . ':'. $this->_port);
	}


	/**
	 * Initiate HELO/EHLO sequence and set flag to indicate valid smtp session
	 *
	 * @param  string $host The client hostname or IP address (default: 127.0.0.1)
	 * @throws Zend_Mail_Protocol_Exception
	 * @return void
	 */
	public function helo($host = '127.0.0.1')
	{
		// Respect RFC 2821 and disallow HELO attempts if session is already initiated.
		if ($this->_sess === true) {
			/**
			 * @see Zend_Mail_Protocol_Exception
			 */
			require_once 'Zend/Mail/Protocol/Exception.php';
			throw new Zend_Mail_Protocol_Exception('Cannot issue HELO to existing session');
		}

		// Validate client hostname
		if (!$this->_validHost->isValid($host)) {
			/**
			 * @see Zend_Mail_Protocol_Exception
			 */
			require_once 'Zend/Mail/Protocol/Exception.php';
			throw new Zend_Mail_Protocol_Exception(join(', ', $this->_validHost->getMessages()));
		}

		// Initiate helo sequence
		$this->_expect(220, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
		$this->_ehlo($host);

		// If a TLS session is required, commence negotiation
		if ($this->_secure == 'tls') {
			$this->_send('STARTTLS');
			$this->_expect(220, 180);
			if (!stream_socket_enable_crypto($this->_socket, true, STREAM_CRYPTO_METHOD_TLS_CLIENT)) {
				/**
				 * @see Zend_Mail_Protocol_Exception
				 */
				require_once 'Zend/Mail/Protocol/Exception.php';
				throw new Zend_Mail_Protocol_Exception('Unable to connect via TLS');
			}
			$this->_ehlo($host);
		}

		$this->_startSession();
		$this->auth();
	}


	/**
	 * Send EHLO or HELO depending on capabilities of smtp host
	 *
	 * @param  string $host The client hostname or IP address (default: 127.0.0.1)
	 * @throws Zend_Mail_Protocol_Exception
	 * @return void
	 */
	protected function _ehlo($host)
	{
		// Support for older, less-compliant remote servers. Tries multiple attempts of EHLO or HELO.
		try {
			$this->_send('EHLO ' . $host);
			$this->_expect(250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
		} catch (Zend_Mail_Protocol_Exception $e) {
			$this->_send('HELO ' . $host);
			$this->_expect(250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
		} catch (Zend_Mail_Protocol_Exception $e) {
			throw $e;
		}
	}


	/**
	 * Issues MAIL command
	 *
	 * @param  string $from Sender mailbox
	 * @throws Zend_Mail_Protocol_Exception
	 * @return void
	 */
	public function mail($from)
	{
		if ($this->_sess !== true) {
			/**
			 * @see Zend_Mail_Protocol_Exception
			 */
			require_once 'Zend/Mail/Protocol/Exception.php';
			throw new Zend_Mail_Protocol_Exception('A valid session has not been started');
		}

		$this->_send('MAIL FROM:<' . $from . '>');
		$this->_expect(250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2

		// Set mail to true, clear recipients and any existing data flags as per 4.1.1.2 of RFC 2821
		$this->_mail = true;
		$this->_rcpt = false;
		$this->_data = false;
	}


	/**
	 * Issues RCPT command
	 *
	 * @param  string $to Receiver(s) mailbox
	 * @throws Zend_Mail_Protocol_Exception
	 * @return void
	 */
	public function rcpt($to)
	{
		if ($this->_mail !== true) {
			/**
			 * @see Zend_Mail_Protocol_Exception
			 */
			require_once 'Zend/Mail/Protocol/Exception.php';
			throw new Zend_Mail_Protocol_Exception('No sender reverse path has been supplied');
		}

		// Set rcpt to true, as per 4.1.1.3 of RFC 2821
		$this->_send('RCPT TO:<' . $to . '>');
		$this->_expect(array(250, 251), 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
		$this->_rcpt = true;
	}


	/**
	 * Issues DATA command
	 *
	 * @param  string $data
	 * @throws Zend_Mail_Protocol_Exception
	 * @return void
	 */
	public function data($data)
	{
		// Ensure recipients have been set
		if ($this->_rcpt !== true) {
			/**
			 * @see Zend_Mail_Protocol_Exception
			 */
			require_once 'Zend/Mail/Protocol/Exception.php';
			throw new Zend_Mail_Protocol_Exception('No recipient forward path has been supplied');
		}

		$this->_send('DATA');
		$this->_expect(354, 120); // Timeout set for 2 minutes as per RFC 2821 4.5.3.2

		foreach (explode(Zend_Mime::LINEEND, $data) as $line) {
			if (strpos($line, '.') === 0) {
				// Escape lines prefixed with a '.'
				$line = '.' . $line;
			}
			$this->_send($line);
		}

		$this->_send('.');
		$this->_expect(250, 600); // Timeout set for 10 minutes as per RFC 2821 4.5.3.2
		$this->_data = true;
	}


	/**
	 * Issues the RSET command end validates answer
	 *
	 * Can be used to restore a clean smtp communication state when a transaction has been cancelled or commencing a new transaction.
	 *
	 * @return void
	 */
	public function rset()
	{
		$this->_send('RSET');
		// MS ESMTP doesn't follow RFC, see [ZF-1377]
		$this->_expect(array(250, 220));

		$this->_mail = false;
		$this->_rcpt = false;
		$this->_data = false;
	}


	/**
	 * Issues the NOOP command end validates answer
	 *
	 * Not used by Zend_Mail, could be used to keep a connection alive or check if it is still open.
	 *
	 * @return void
	 */
	public function noop()
	{
		$this->_send('NOOP');
		$this->_expect(250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
	}


	/**
	 * Issues the VRFY command end validates answer
	 *
	 * Not used by Zend_Mail.
	 *
	 * @param  string $user User Name or eMail to verify
	 * @return void
	 */
	public function vrfy($user)
	{
		$this->_send('VRFY ' . $user);
		$this->_expect(array(250, 251, 252), 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
	}


	/**
	 * Issues the QUIT command and clears the current session
	 *
	 * @return void
	 */
	public function quit()
	{
		if ($this->_sess) {
			$this->_send('QUIT');
			$this->_expect(221, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
			$this->_stopSession();
		}
	}


	/**
	 * Default authentication method
	 *
	 * This default method is implemented by AUTH adapters to properly authenticate to a remote host.
	 *
	 * @throws Zend_Mail_Protocol_Exception
	 * @return void
	 */
	public function auth()
	{
		if ($this->_auth === true) {
			/**
			 * @see Zend_Mail_Protocol_Exception
			 */
			require_once 'Zend/Mail/Protocol/Exception.php';
			throw new Zend_Mail_Protocol_Exception('Already authenticated for this session');
		}
	}


	/**
	 * Closes connection
	 *
	 * @return void
	 */
	public function disconnect()
	{
		$this->_disconnect();
	}


	/**
	 * Start mail session
	 *
	 * @return void
	 */
	protected function _startSession()
	{
		$this->_sess = true;
	}


	/**
	 * Stop mail session
	 *
	 * @return void
	 */
	protected function _stopSession()
	{
		$this->_sess = false;
	}
}
